[WhatsADSM]

So I have finally pulled the trigger on swapping my Federal S2 Elise to a Honda K24, and figured it was only appropriate to start this thread.

I know there have been lots of little bits of information about the swap here or there and a few good build threads from various people (MNlotus, and MacLotus come to mind). Here I am hoping to not only chronicle my K-series build, but also provide some resources and information for people who are considering the swap themselves.

While I do have a fair amount of experience in building and swapping cars, I am by no means an expert. The same holds true for Honda tuning. If you see information here that looks incorrect, or have something to add please let me know and I would be happy to change it.

I will do several "single subject" write ups throughout the thread that can be used as a reference for those who are considering the build. I will link them directly here within the first post so there is a quick and easy table of contents so to speak.

As for the progress of my particular build I will document that throughout this thread and will doubt I will setup links here in the first post unless people really want.

Why consider the Honda K-series?

K-series swap basics

Selecting the right K-series

 

[WhatsADSM]

Why consider the Honda K-series?

Let me first start off by saying this. I have NOTHING against the Toyota 2zz, and in fact think in general it is a very underrated engine within the sport compact world. In fact before actually pulling the trigger I was very strongly considering either supercharging or turbocharging (along with a light build) the 2zz I had in the car. However once I weighed all of my options I ultimately ended up choosing the K-series. MY reasons for choosing it are as follows and I will elaborate further:

• Reliability
• Performance
• Swap options
• Aftermarket support
• Competitive overall cost of ownership

Reliability:
So this one pretty much goes without saying. Honda has historically been known for making very reliable engines and the K-series is no different. While most engines have a weakness here or there the K-series is generally void of issues. There are countless people with RSXes, TSXes, Accords, Elements, CRVs, etc. etc. out there with hundreds of thousands of miles on them with nothing more than routine maintenance. The very fact that it has such a large installation base within Honda's line up really proves how much they believe in the reliability of the engine and how much you should too.


Performance:
Again this one goes without much to say. While the lower end K-series engines as found in the Accord don't seem like much, take a quick look at what has been accomplished on the higher output versions such as the RSX type S, TSX, or Type R variants. It is a common place to see naturally aspirated K20s with 2.0l of displacement making over 120hp/liter with mild bolt-ons. Engines with more aggressive builds make into the 140hp/liter naturally aspirated all while maintaining fantastic drivability and reliability. On the forced induction side of things boosted K-series engines, even in stock form, return very large power gains from very little boost. All of this is possible due to a mix of modern technology like variable cam timing, variable lift, heads that is STOCK form flow almost 300cfm, etc. etc. While the 2zz is certainly a performer in its own right, it simply can not compare.

A small note here. The weight of the K-series engine is essentially the same as the 2zz. I have heard crazy stuff like it is 100 lbs more, or it is 100 lbs less. Fact of the matter is it depends on lots of little things (K20 block versus K24), clutch/flywheel, exhaust/intake. Expect that N/A to N/A 2zz and K-series are very close and it comes down to specifics.

The Honda an Toyota engines & transmissions are almost identical in weight. You may reduce weight during the swap if your new mounts & exhaust system are lighter than stock.

Swap options:
One of the beauties the Honda K-series swap is that it is such a "scalable" swap. By that I mean there are options for very simple and low budget all the way to complex and high budget. I really appreciated this fact as I went through my selection process myself. I never felt as though I was going to be backed into a corner. I could choose between K20, or K24, Naturally aspirated or supercharged or turbo charged. There is truly an option for everyone. I will elaborate more thoroughly in a single subject about "Selecting the right K-series"


Aftermarket/OEM support:
This is what made me make the jump. I can't stress enough how much this differs between the Honda K-series and the Toyota 2zz. The fact is economy of scale DOES matter and there are strength in numbers. Let me remind you that every RSX released has a K-series engine, the Civic has the K-series, the Accord uses it, as does the Element, the CR-V, and the TSX. The very fact that it is in such widespread use means that aftermarket companies have FLOCKED to it and created tons of parts for it. If I were to go look up cams for a K20/K24 I would find Skunk2 with 3 sets, Brian Crower with 3 or 4 sets, Toda with a 2 or 3, Mugen with a few, not to mention all of the smaller but great companies like IPS, Drag Cartel, Kelford, Blueprint, etc. etc. You want an intake manifold? Take your pick from a handful of OEM options, and options from Skunk 2, IPS, Excessive, Hayward, etc. Want some ITBs? Sure why not there are 2or 3 companies selling a few kits each.

Note only is there a large aftermarket part list, but there is also a lot of competition amongst aftermarket companies which drives down cost of parts considerably in comparison to the 2zz. Want a new OEM engine harness? That's less than $300. Want an OEM intake manifold with great flow? Under $250. Forged piston and rod sets? $800


Competitive overall cost of ownership:
So this one is related in part to my point above. But I feel the need to spell it out explicitly here. I have built and helped people build lots of cars... and one of the most common mistakes I feel people make is failing to see the "big picture". Many times people get hung up on the upfront costs associated with a swap such as this (or a LSx into XXX chassis, or SR into Nissan 240, etc). When the better way to look at it is: At the end of the day when all is said and done.. how much do I need to spend to do what I need to do and how much future potential exists?

Sure the idea of spending a few thousand dollars to swap in one 4-cylinder for another doesn't look very appealing. But then consider, once swapped how much does it cost for me to add more power? Once swapped how reliable will it be? Once swapped do my transmission woes go away? Once swapped do I have more options in the future?

With the Honda K-series in the answer to all the above is VERY good. Sure it costs time and money to get the K-series into your car... but once you are there you now have a wonderful platform. A platform where you can build a naturally aspirated engine for a few thousand that surpasses most of the supercharged 2zz builds. A platform where the stock longblock has been pushed to over 600whp on boost. A platform that has reliability in both the engine and a transmission that doesn't fall apart with 300whp. A platform where your potential is almost anything you can dream up. :up:

Edit: One thing to remember with all of these swaps is that you are seriously modifying the vehicle beyond its original form. So while the K-series may be an all around better engine and vastly improve the performance of the vehicle, you must realize not everyone may think the same way you do. When it comes time to sell a largely modified vehicle realize you will never get the money out of it that you put in (or any where near that). You will also have a smaller buyers market. Cars are a labor of love and I only mention cost/value here, assuming that you have already decided that you are going to modify the car dramatically. This is simply a comparison of cost of ownership between one extreme modification (K-series) to another like built N/A,Supercharged,Turbocharged 2zz.

 

[WhatsADSM]

K-series swap basics

Again by no means am I the expert here. I have done quite a bit of research and yet I know there are others out there with lots of good information. If you are one of them something looks incorrect or you think something should be added post up or let me know otherwise and I'll fix/add it.

So I know there are lots of various threads out there on Lotus Talk that talk about what is needed for the swap and who offers the kit. Additionally there are a few threads talking about the various kit manufacturers out there. I guess my purpose here is to outline the basics of the swap and who offers parts to help you with it. This section is intended to just give the basics and there will be single subjects on most of these topics later.

Kit manufacturers:
Just as I did in another thread. I am going be brutally honest here, and this is what I know as of this writing.

If you decide to go K-series you truly have 2 options. There are other companies if you have a NON-Federal Elise/Exige. However this thread is about the K-series into the Federal (US) Elise/Exige which came with the Toyota 2zz:
1) Joe McCarthy / Prototype Racing (I believe there were other names for his company in the past but as of now this is it)
Joe M. is clearly a very smart fellow and those who have his kits can not say enough about the quality of what was delivered. His kits have been out the longest, they are well tested, proven, and I'd venture a guess that he knows the MOST about the K-series into a Federal Elise, period.

HOWEVER, it doesn't take more than a few searches on here and Google to find lots of people who have had bad experiences with Joe M. and/or his company. There were lots of stories of undelivered or slow parts, failed promises, etc.

My only other issue with Joe/Prototype Racing is the sheer cost of the kit. Last I checked it was $9000 for just the kit. But I would like to add that it was a VERY complete kit and included everything from little shields, to mounts, axles, wiring, and even the Hondata K-Pro (flashing software), and interface to stock dash.

I guess my take-away for Joe M/Prototype Racing is if you are very serious about a K-series, want a great kit that is complete, tried and true, and money is no object Joe M. is definitely to be considered. However tread carefully and watch over the process very carefully as all of his kits are hand built and nothing is in stock and there have been issues in the past.


2) Innovative Mounts
These guys are new to the K-series LOTUS game, but not new to fabrication and certainly not new to the K-series engine or swap kits. Honestly I think it is great that another company is getting involved and giving us an option for this swap.
Innovative mounts has a different business model than Prototype. They are more of a large scale fabrication house. They do mount kits for various other vehicles primarily Hondas. This includes some K-series mounts and kits for various Honda chassis. They sell their parts with much higher volume and sell parts in a more "off-the-shelf" fashion as opposed to one-off custom kits as done with Prototype Racing.

The Innovative kit is much more competitively priced, and by my rough guess is roughly half of the Prototype kit. For the most up to date pricing see Innovative's website:
K-Series

The biggest issue with the Innovative kit (at least at this time) is that it is largely untested and not as complete as the Prototype kit. Although again they have experience with the K-series and certainly deliver quality work. Additionally not all of the parts needed for the kit are available (per the web), although I believe that will change within the next month or two.

The take-away for Innovative mounts is that the kit is more for the DIYer that still wants a quality kit, isn't willing to pay a ton of money for a kit, but also has more fabrication skills. Expect if you go with this kit immediately that there may be some small things that you will need to deal with or fabricate.



Swap Basics:
Alright, lets get to it. So what we are trying to do here is swap a K-series into a Lotus Elise/Exige. While removing one Japanese 4-cylinder for another doesn't sound like much this isn't your Lego set and there are quite a few things that need to be resolved.

Remember I will be doing single subjects on most of these items, so I will only provide the basics here.

Engine:
All of the kits are designed around the K20. However the K-series is a rather modular engine and the K24 externally is almost identical to the K20. The only real difference is that the deck height (block height) is about 19mm higher on the K24. If you decide to go with a K24 you simply need to get the CR-V (or P2R) bracket. Additionally you will need to realize that all of the connections (mostly important for intake, and headers) will be slightly higher than in the K20.

There are lots of engines and combinations to choose from. I will not get into it here, I plan on a "Selecting the right K-series" post.

Transmission:
The kits are designed around the transmission from a 02-04 RSX. They are available in either 5 or 6 speeds depending upon which vehicle they are sourced from. You may be able to use a transmission from a newer vehicle, however I believe some things will need to be converted (I am not the expert here). It is simplest to plan on a 02-04 RSX transmission.

Wiring:
Both the Lotus and the K-series have rather modular wiring. This means there is a fairly straight forward delineation between the harness which runs to the engine, and the body harness. The basic premise here is to use the stock RSX type S engine harness from 02-04, which will provide you with the correct harness to run the engine. You will then need to adapt a few signals into the body of the Lotus, which is where the swap harness (from the kit manufacturer) and a little custom wiring comes in.

Dash interface:
While we are on wiring. One of the more complex areas of the swap is getting a dash to work. The stock Lotus dash is a CAN based dash and would need a conversion box to run. This conversion box is only available at the moment with the Prototype Racing kit, I believe it will be available with the Innovative kit at some point. Otherwise clearly you can run a race dash such as Racepac.

Mount Kit:
Pretty self-explanatory. We need to mount the K-series into the Lotus rear subframe while maintaining all clearances, axle angles, good weight distribution etc. This is a big part of the "kit". I know innovative has 3 mounts as of now, not sure if Prototype has 3 or 4 total.

Axles:
Again self-explanatory. The transmission splines and location are now different than the 2zz. So we will have custom axles provided as part of the kit which use Honda inboard CVs and Lotus outboard CVs with the stock hubs (at least that is the case with Innovative)

Shifter linkage:
The stock RSX transmission was designed to be used with a Honda shifter box and in a FWD layout. We now need something to convert that to a mid-engine layout and the Lotus shifter box. Again this is an important piece which is provided as part of the kit

Drive-by-cable Pedal and Throttle Cable (06+ Elise/Exige):
We will replace the drive-by-wire system on 06+ Elise/Exige with a standard drive-by-cable setup as used in the Honda. We will need either a custom pedal/cable as provided by Innovative, or swap to the stock 05 Elise pedal.

Miscellaneous Lines:
Clutch hydrolic lines, fuel lines, water lines, oil cooler lines will all have to be resolved. Although most are very straight forward.

Headers:
Custom headers (and potentially exhaust) will need to be utilized for this swap. Headers are included with the Prototype kit, and available through a 3rd party (Hytech) for the Innovative kit. Of course you can always bring your car to a local fabrication shop as well.

(Optional but recommended) Performance Upgrades:
ECU/Standalone upgrades (included with Prototype), Clutch upgrades, intake manifold upgrades, etc. etc. I honestly can't imagine swapping in a K-series without doing any bolt-ons. Once swapped you now have millions of options open to you... I suggest you plan and budget to use them!

 

[WhatsADSM]

My build: Status Update 03/02/11

So it all started right around the turn of the new year when I decided to go ahead with a winter/spring project.

At the time I was very unsure of what route I was going to take in terms of the power modifications. On the list of options was. BOE TVS kit (which is now a next generation "Rev" kit), the upcoming Radium "Stage 2" kit, and a custom turbo kit based on the MWR manifold but again for the 2zz. I then spotted the talks about the K-series swap kit from Innovative and got in touch with them about it.

In the mean time I figured no sense in keeping the stock 2zz in there anyways since it was going to be a (mildly) built 2zz or K-series. So I pulled the rear clam, front clam, and engine/transmission:

After doing some thinking for the next week or 2 I finally decided that it would be a K-series kit, but not sure what exact variation. The reasoning behind it was essentially what I posted up in the "Why K-series". Truthfully the k20 is the engine that always *should* have come in this car and its a shame that it's not. One of the best chassis makers in the business combined with one of the best engine makers in the business... what's not to like.

Well price of course. But once you add up and realize everything you actually get with the K-series (power, engine reliability, transmission reliability, end user EFI programming, tons of aftermarket, etc, etc) it makes sense.

So with my mind set on the k-series I officially ordered all the parts from the Innovative kit except the headers (which at the moment are actually through a seperate company Hytech which is known for their great custom Honda headers).

I then began researching exactly which k-series engine I should choose. I have been a forced induction guy almost my whole life, and so I was naturally drawn to that route. And to be honest, the most cost sensitive thing to do assuming you want forced induction is to simply choose the k20a2. The good part about the k20a2 is that it is the least expensive of the more "high output" k-series (k20a, k20a2, k24a2), the swap kits are actually designed electrically to work with the k20a2 (02-04 RSX-S), and best of all they are known to take ridiculous amounts of power on the stock bottom end. So for my goal of around 350whp a boosted k20a2 fit the bill perfectly.

So I began looking for a k20a2 engine and transmission and searched for a few days in the classified ads on k20a.org and clubrsx.com and stumbled upon someone looking to sell his k20a2 engine, harness, and ecu with low mileage for 1600. So I pulled the trigger.

Now hindsight is always 20/20, but I made a minor blunder here. My biggest mistake was assuming the Rotrex k20 kit would fit. After doing some more research and talking more to Innovative I realized that I highly doubt, in fact I can almost guarantee, it wont. Reason being is that the Rotrex kit mounts the supercharger down by the A/C. However the A/C area is probably the tightest area in terms of fitment in the Elise, even in stock form. If you look closely the A/C unit that is in the stock Elise is a very small unit that I believe was modified specifically for fitment in the Lotus. So therefore a k20 with the k20 A/C unit won't fit, which throws the Rotrex idea out the window since the Rotrex is bigger yet.

So now here I am with a k20a2, and no way to go with the Rotrex. So I had 3 options at this point:
1) Keep the k20a2 and build it N/A
2) Keep the k20a2 and just do a custom turbo kit
3) "Cut my losses" and find a k24 bottom end and build a N/A K24/K20 (Frankenstein build in Honda terms)

So to be honest option 1 (although it was the cheapest) simply wouldn't get me close enough to the power I wanted... I could have probably got 240-250whp and some decent torque maybe 160 ft-lbs, but that was about it.

I was now between option 2 and option 3. Undoubtedly with a turbo k20a2 I could make TONs of power. I suspect I could make 400whp fairly easily with a fairly low spool threshold and not too much boost. The care would have been blisteringly fast in a straight line, and considering I have access to a friend who does some custom fab work it actually wouldn't have been to much money either.

Yet I choose to build a naturally aspirated K24. Why? Well the Elise isn't about being blisteringly fast in a straight line. As well all know it is MORE about being fast in the corners, its more about simplicity, having great throttle response, and most of all being fun to drive. Swapping in an N/A K24 is basically taking everything we all like about the Elise and turning it up a few notches. It keeps the balance and fun factor of the Elise, while giving it the guts to run with the Z06s, GTRs, 911s etc in a straight line. Putting a turbo on it would be faster yet in a straight line, but it would take too much away from throttle response, simplicity, and the fun factor. This is exactly why you find most people that swap to K-series swap in a K24.

So with my mind finally made up I pulled the k20a2 cylinder head off of the engine I bought, and shopped around for an engine builder and exactly how I was going to build the engine.

My engine builder will be RS Machine out of Norwalk, CA.
My parts shopping yielded a mild K24/K20 build which I guesstimate will make somewhere between 270whp-300whp and 200+ft-lbs of torque from 3000 RPM -7000 RPM where it will probably taper off a bit to the 8400ish revlimit. It will consist of the following:

Stock K24A4 (Honda accord/element) block and 99mm crank. Stock sleeves bored .020 over
Wiseco 12.5:1 forged pistons
Eagle forged H-beam rods
K20A2 (RSX-S) oil pump, and aluminum oil pan
Hytech or blueprint oil baffle kit (dry sump is too rich for my blood)
Stock K20A2 (RSX-S) head, with a light port around the at the valves. These heads don't need much as they flow almost 300cfm at .550 out of the box
Supertech dual valve springs, with steel retainers
Kelford Type-B cams (IN 306*/13.5mm, EX 312*/12.5mm)
Skunk2 Intake manifold, and 74mm throttle body
775cc injectors (so I can run 93 oct or e85)
Golden eagle fuel rail
FuelLab FPR, Custom -6 A/N Lines.
Hondata K-pro ECU.
Headers are still up in the air. Either I will get a custom set from Hytech if they are cheap enough, or else I will have to have them made and my buddy Jim says he is up for the challenge.

Other parts that I plan to fix/add during the process:
Surge Tank
BOE toe links
Oil cooler fix (either replace with a single cooler+fan in back, or replace all lines and use the stock front mounted coolers with the K24)
New clutch
LSD (Helical. Either Quaife, or Wavetrac, maybe MFactory)

As for the swap parts. Well they have been a bit slow coming, which I was kind of expecting with it being a new kit. However what has arrived so far has been beautiful.. Very quality pieces. :up:

So far I have:
Driver mount, rear mount
Fuel canister (although I will be going a different route there)
Throttle pedal.

I was told the clutch line, passenger mount, and throttle cable/bracket for the kit should be ready very soon (like end of the week ish).

Additionally, the way Innovative does the axles for this kit is to use Honda (or is it custom) inner CVs, custom axles, and the stock Lotus outer CVs. So I pulled the CVs from my stock axles and they now have them. To pull the CVs you simply pull off the clamp, slide the boot down the axle, and (with a plastic hammer or mallet) hit the outer CV until it comes off the axle. Some CVs are held on by a circlip that can be directly accessed once the boot is off, however in the case of the Lotus the clip is internal to the CV so it just takes a little "persuading" with the hammer and they will come off. If you go the Innovative route. When you send them the CVs to make your axles, you will need to send them the CVs, the boots, and the circlips:

 

[6i9]

Thank you for taking the time to document the K Swap comprehensively. Very great to see this info out there in an organized manner...also becoming more and more tempting as it seems easier and more accessible than ever...

 

[jah29]

I'm definitely going to do this swap, but since I want to do it all myself and I'm not very experienced, I'm going to have to be at least the tenth

So I very, very much appreciate this thread!

Very curious about firewall space with the innovative kit. Specifically which intakes and superchargers will fit?

Thanks,
Justin

 

[yellow99s]

Fantastic! I'm planning on going this route after the new paint, glad to have a real resource now. Thanks for taking the time

 

[MNlotus]

awesome!! good to see another k series swap, you will be happy once you finished.
any idea what you plan to do withe the motor? S/C, turbo, or NA?

 

[Maxster]

Have you considered the MWR Elise V330 - 3.5L V6 swap?

 

[jds62f]

Impressive start. Will be watching!

 

[4380r]

Sounds like a great project and looking forward to see what you come up with.

I only suggest that the Competitive Cost of Ownership is overlooking the likelihood that ultimately such a swap will either lower the resale value or simply make it more difficult to sell. Even if this markedly 'improves' the car overall, with some exceptions most folks see these kinds of projects as potentially fraught with hidden problems the owner either didn't address properly, and/or is looking to hide/unload.

I think this kind of project needs to be fully rationalized simply on the "I want to do it" basis, and not with any kind of overall financial argument.

Best of luck.

 

[WhatsADSM]

I'm definitely going to do this swap, but since I want to do it all myself and I'm not very experienced, I'm going to have to be at least the tenth

So I very, very much appreciate this thread!

Very curious about firewall space with the innovative kit. Specifically which intakes and superchargers will fit?

Thanks,
Justin

Great question, and you have good reason to wonder. The intake side of the engine has the most clearance issues.

So I will touch on in it a little bit in the which k-series should I get part. However the basic premise is that there are 3 major supercharger setups in the world of the K20/K24. The CTSC (Comptech Supercharger), JRSC (Jackson Racing Supercharger) and the Rotrex (provided by Kraftwerks). Without getting into too much detail on each of those, at this point I am comfortable saying the Rotrex (IMO best of them) will not fit due to the location. Although they plan to come out with a new kit that mounts the supercharger up high and provides a new intake manifold and is designed for the 06+ civic SI. The kit is not out yet, but I believe it will have a much better shot at fitting.

As for the CTSC or JRSC; the JRSC is the most widely used and I can only go based on pictures, but it looks like it would be VERY close. It may fit or it may not. Without actually having one or knowing the exact dimensions I won't know. Only other thing I can say is that I will take a few measurements with the Innovative mount kit once I have the engine in. Also an important point to note, is that at one point Joe M. did have a supercharger on his K20. And explicitly told me the M62 (supercharger used in JRSC and CTSC) will work. I'm not sure if he was using an off the shelf kit or modified it slightly, but none-the-less it definitely gives hope for that option.

As for intakes:
In other threads it has been stated that the skunk 2 and RBC both fit, with the skunk 2 having the most clearance. By deduction and talking to a few engine builders that likely means the RRC intake manifold would likely fit as well.

awesome!! good to see another k series swap, you will be happy once you finished.
any idea what you plan to do withe the motor? S/C, turbo, or NA?

N/A, a very similar build to yours :up:
Once I finally get home and get a chance to post up my build I will elaborate a bit more.

Have you considered the MWR Elise V330 - 3.5L V6 swap?

Considered it a little.
Still seems a bit cost prohibitive and through the grape vine I heard it wasn't fully sorted out. So between the budget and lingering questions about the actual state of the swap and parts, I decided against it.

Sounds like a great project and looking forward to see what you come up with.

I only suggest that the Competitive Cost of Ownership is overlooking the likelihood that ultimately such a swap will either lower the resale value or simply make it more difficult to sell. Even if this markedly 'improves' the car overall, with some exceptions most folks see these kinds of projects as potentially fraught with hidden problems the owner either didn't address properly, and/or is looking to hide/unload.

I think this kind of project needs to be fully rationalized simply on the "I want to do it" basis, and not with any kind of overall financial argument.

Best of luck.

Totally agreed in terms of selling and rationalizing based on "I want to do it". I'll add that note (although I still think project modification cost and value is VERY important).

As with all modifications (especially ones that swap engines or drastically change the power output), u will never get what you put into it. Financially the most intelligent thing to do is leave it stock. Then again the most financially intelligent thing to do was to buy a civic and drive it, but money isn't everything

 

[dstevens]

Can you update / merge your posts with this information? (start of a FAQ?)

Transmission
TSX transmissions use a different case, and cannot be used with the current swap kits. However, the shafts/gears from the TSX transmission can be swapped into any other transmission.
There are two types of speed sensor supplied with transmission - final drive driven and 3rd gear driven. If you wish to use a Honda ECU then you will need a transmission case with a final drive type output. These are found on the 02-04 RSX & 02-05 Civic style transmission cases. If you have a later model transmission then the clutch side of the case can be swapped over for a 02-04 RSX style case for a cost of about $250 for a new case from Honda.

LSD
You also will want a LSD of some sort. The Honda LSD works ok as long as you do not drag race on slicks. The Quaife is equivalent to the Honda LSD but stronger. Other LSDs are available (Mugen, Spoon, OS Giken).

ECU
If you have any plans to use the Honda ECU with Hondata then you will need to 02-04 RSX wiring harness (NOT the 05+), as well as the 02-04 transmission case as outlined above. Don't be tempted by other people using 05+ harnesses with an adapter to an 02-04 ECU - this does not work correctly.

Superchargers
Neither the CT or JR supercharger are intercooled. Both have horrible throttle body to supercharger adapters which restrict power. The Kraftwerks produces good peak power but very little gain anywhere else in the rev range.

Weight
The Honda an Toyota engines & transmissions are almost identical in weight. You may reduce weight during the swap if your new mounts & exhaust system are lighter than stock.

Reduced resale cost swapping the 2ZZ for a Honda engine? You're joking of course...

 

[yellow99s]

The Jackson racing supercharger for the civic si sits verticle instead of horizontal like in the Rsx and should offer much better clearance. My last car was a jr blown Rsx and the guys on clubrsx.com have assembled an air to water intercooler, just a thought.:up:

 

[WhatsADSM]

Ok, I added my first status update above! :coolnana:

Can you update / merge your posts with this information? (start of a FAQ?)

Transmission
TSX transmissions use a different case, and cannot be used with the current swap kits. However, the shafts/gears from the TSX transmission can be swapped into any other transmission.
There are two types of speed sensor supplied with transmission - final drive driven and 3rd gear driven. If you wish to use a Honda ECU then you will need a transmission case with a final drive type output. These are found on the 02-04 RSX & 02-05 Civic style transmission cases. If you have a later model transmission then the clutch side of the case can be swapped over for a 02-04 RSX style case for a cost of about $250 for a new case from Honda.

LSD
You also will want a LSD of some sort. The Honda LSD works ok as long as you do not drag race on slicks. The Quaife is equivalent to the Honda LSD but stronger. Other LSDs are available (Mugen, Spoon, OS Giken).

ECU
If you have any plans to use the Honda ECU with Hondata then you will need to 02-04 RSX wiring harness (NOT the 05+), as well as the 02-04 transmission case as outlined above. Don't be tempted by other people using 05+ harnesses with an adapter to an 02-04 ECU - this does not work correctly.

Superchargers
Neither the CT or JR supercharger are intercooled. Both have horrible throttle body to supercharger adapters which restrict power. The Kraftwerks produces good peak power but very little gain anywhere else in the rev range.

Weight
The Honda an Toyota engines & transmissions are almost identical in weight. You may reduce weight during the swap if your new mounts & exhaust system are lighter than stock.

Reduced resale cost swapping the 2ZZ for a Honda engine? You're joking of course...

Awesome thanks for chiming in. You are definitely one of the experts in this area

I will merge some of that info into the "K-series" swap basics section. Some of the detailed info... Like about the transmission/LSD/ECU I will add to my more advanced single subjects that will outline each of those in detail. Again thanks for the info/help :clap:

As an aside about the super chargers. There is a company MercRacing that modifies the JRSC M62 kit for the RSX to add a basic air-to-water intercooler. Seems to be fairly well reviewed. In general though the M62 is just too small for the K-series, even the K20. Just really isn't designed to be pushing 300whp of air... take a look at the compressor map for it once, anyone doing that is WAY off the map.

As for the Rotrex, I agree they are very peaky due to its centrifical nature. So yea a "350whp" Rotrex setup is a little misleading because it is so peaky. I did an overlay with a 300whp N/A K24, a 300whp IC'd JRSC setup, and a 350whp Rotrex. And you are right, if you compare area under the curve the rotrex does not have (350/300) more area. HOWEVER, it still does have more area under the curve than either the N/A or M62 when considering about 5000RPM to redline which is where most of our racing takes place. IIRC it is kind of like a 325-330whp N/A setup. So in my eyes that is still the way to go for cheap power production IF IT FIT (which it doesn't).

The Jackson racing supercharger for the civic si sits verticle instead of horizontal like in the Rsx and should offer much better clearance. My last car was a jr blown Rsx and the guys on clubrsx.com have assembled an air to water intercooler, just a thought.:up:

Yup I think the Air-to-water you are referring to the MercRacing version I mentioned above.

I had no idea the civic SI kit was vertical like that. Awesome info! That would definitely help in terms of fitment. I will definitely add that to my writeup about which k-series route to go. Thanks :clap:

 

[GR82DRV]

Thanks for such a well written and documented report. Please post on the Midwest forum whenever you decide to display your finished work in-person in the Wisconsin area. I'd love to see the car.

 

[yellow99s]

Just noticed your in Milwaukee, you familiar with King Motorsport (Mugen)? They're one of the "heavy hitter's" in the Honda scene, a wealth of experience, parts and tuning right in your backyard.

 

[WhatsADSM]

Thanks for such a well written and documented report. Please post on the Midwest forum whenever you decide to display your finished work in-person in the Wisconsin area. I'd love to see the car.

Will do!

Just noticed your in Milwaukee, you familiar with King Motorsport (Mugen)? They're one of the "heavy hitter's" in the Honda scene, a wealth of experience, parts and tuning right in your backyard.

Yea I have heard of them but haven't really worked with them until now. I have only talked to them so far, and they have been very friendly and helpful. Its good to know that if I get stuck on something Honda related I can always just bring it up the road

 

[dstevens]

AC
The retain AC you will need to use the Toyota AC compressor, with new brackets and hoses. The Honda part is far too big to fit.

The Civic Si vertical JR setup is horrible. When running on the dyno we found that the manifold reversion was so bad that if you take off an unused vacuum cap it would blow raw fuel up in the air at various rpms. When you look at a used manifold the back wall of the plenum is always clean from the fuel blown out of the runners.

My take on the Rotex vs Eaton is based on time to speed measurements I made on two stock Civic Si's with only the blower. I always prefer real world testing to dyno runs and theoretical calculations. The Rotrex made 360 hp, the Eaton 285 hp, but the Eaton was faster with runs up to 4500 rpm, the same as the Rotrex with runs to 7000 rpm, and slower with runs to redline. It depends on your driving - in a street car, I don't start at 7000 rpm when I put my foot down - it normally is 2500 - 3500 rpm. Even when racing you have to look at your corner mid point rpm. A little time lost out of the corner takes the whole straight to claw back, as any drag racer who has got a poor start will know, so the low down engine output is important to me. However, the Rotex has a better manifold (with actual runners) so does run better than the JR setup and also is also intercooled, so would be better in hot weather.

 

[speedybishi]

Thanks for such a well written and documented report. Please post on the Midwest forum whenever you decide to display your finished work in-person in the Wisconsin area. I'd love to see the car.

+1

The whole process sounds fun and exciting. Do you have an expected time frame for completion?